If you could raise a wolf in your home, would it grow up to be any different from a typical pet dog? In a rare experiment with tame wolves, a Hungarian scientist tried to answer this question — and the results hinted at one major difference between dogs and wolves.

Five of the pet dogs barked or growled at the experimenter when she was threatening, or tried to attack her. None of the wolves did. . . In fact the wolves did not seem particularly interested, opting instead to sniff the ground, walk away, or stay lying down. Wolves looked away from the experimenter within the first two seconds of her approach, which was significantly earlier than the dogs.

Gácsi et al suggest several possible explanations of the wolves’ behaviour, including “that wolves did not consider this test as representing a conflict or competitive situation. Thus, their gaze-averting behaviour may be due to their ignorance of the human’s behaviour or their general tendency to avoid human gaze”.

Here you can see photographs of the "friendly" approach, and it gives you a sense of what the setting was like for these observations.

Companion Animal Psychology suggests that the wolves in the "aggressive approach" experiments were aware of the human's behavior because they mostly did change what they were doing, even if it was just walking away or sniffing the ground. So it's possible the wolves had a much better sense of what was actually a threat than the dogs did — after all, these were controlled experiments and the aggressive strangers were just scientists pretending to act aggressive.

I also wondered if the wolves reacted that way because, unlike the dogs, they weren't going to bother putting on a show of aggression until it was absolutely necessary. I couldn't help but imagine the wolves thinking to themselves, "Sure, annoying human, just come a little closer — then I'll just bite the hell out of you. But until then, I'm going to relax."

My little wolf fantasy aside, it's worth noting that another major difference between the dogs and wolves was the eye contact the animals made with their human companions. The dogs looked over at the human for cues, but the wolves seemed content to decide on their next move without checking in with their human. Dogs may be more socially connected to humans than wolves are. Or wolves may be socially connected enough to humans to know that they can conserve their energy for the real threats.